Vehicle trailers facilitate the transportation of various goods. In general, a trailer is pulled by a towing vehicle and can be used to temporarily expand the shipping capacity of the towing vehicle. In addition to a hitch that mechanically attaches the trailer to the towing vehicle, some trailers are equipped to receive electrical signals. For example, brake lights and directional indicators of the trailer can be controlled from the towing vehicle through various electrical signals received from the towing vehicle. When the towing vehicle slows, the brake lights on the trailer will illuminate. Likewise, the directional indicators illuminate with the directional indicators of the towing vehicle.